JP5233500B2 - Power supply control circuit and power supply control method for portable electronic device - Google Patents

Description

  The present invention relates to a technique for controlling a power supply to each functional unit in a portable electronic device using a secondary battery such as a mobile phone as an operation power supply.

  Mobile electronic devices such as mobile phones have been improved in performance and functionality in terms of their functions, and there are many types and numbers of functional devices accommodated in the devices, and power consumption is also increasing. In a portable electronic device, a secondary battery is used as a power source. However, when the battery is used as a power source, the output voltage decreases with the use time, so that power control corresponding to the output voltage is required (Patent Documents 1 to 5). Etc.).

  In general, a cellular phone or the like regularly monitors a battery voltage using an AD conversion circuit in order to display a stage of the remaining battery capacity. The remaining battery capacity is displayed based on the value acquired from the AD converter circuit, but when the discharge progresses and eventually becomes lower than the operating voltage of the mobile phone, a display prompting the user to charge is displayed, and the entire system enters a sleep state. .

  On the other hand, in recent mobile communication devices, a voltage detector for monitoring battery voltage is widely used as one of power supply controls in order to ensure operation at a low voltage. In portable communication devices and the like, a plurality of voltage detectors constantly monitor the power supply voltage due to the multi-function, and the power necessary for each function is turned on / off by detecting a certain voltage.

  At that time, when the battery voltage falls below the operable voltage of the communication device, there is a case where a certain function needs to be operated. For example, if a non-contact IC card function such as FeliCa (registered trademark), which is also used for functions such as commuter passes, is installed, the mobile communication device is used while riding the train, and the battery is Even when it is consumed, it is necessary to secure power to exit the ticket gate. Therefore, even if the battery voltage falls below the operable voltage as a portable communication device, it is necessary to configure the power supply system so that only a specific device can operate.

  FIG. 8 is a block diagram showing the configuration of a power supply system of a conventional portable communication device, for supplying power to the Li ion type main battery 1, voltage detectors 20 and 30 monitoring the battery voltage, and each device. System power supply circuit 4, communication device 5 such as baseband control, display device 6 such as LCD display, interface 7 such as I / O, application device 8 such as sound source and camera, CPU and memory A control input device 90 such as a key input, a data input unit 10 such as a key input, a low voltage drive device 12 that is driven even after the system is shut down, such as Felica and a clock function, and a power supply circuit 13 for the low voltage drive device.

  The voltage detector 20 for system power supply monitors the battery voltage of the main battery 1 and performs control to turn on the system power supply circuit 4 when the battery voltage becomes equal to or higher than a predetermined voltage (hereinafter referred to as release voltage). Then, the power supply of the main battery 1 is supplied to the device connected thereto, and when the battery voltage becomes equal to or lower than a predetermined voltage (hereinafter referred to as a detection voltage), the system power supply circuit 4 is controlled to be turned off. Shut down the device connected to it.

  The voltage detector 30 for the low voltage drive device monitors the battery voltage of the main battery 1 and when the battery voltage becomes equal to or higher than a predetermined voltage (hereinafter referred to as a release voltage) that enables the low voltage drive device to operate. The power supply circuit 13 for the low voltage drive device is controlled to be turned on to supply power to the main battery 1 to the low voltage drive device 12, and the battery voltage becomes equal to or lower than a predetermined voltage (hereinafter referred to as a detection voltage). At this time, the low voltage driving device 12 is shut down by controlling to turn off the power supply circuit 13 for the low voltage driving device.

  FIG. 9 is a circuit configuration diagram showing an example of a voltage detector 20 for a system power supply and a voltage detector 30 for a low-voltage drive device used in a power supply system such as the above-described conventional portable communication device.

  When the battery voltage falls below the detection voltage, these voltage detectors turn the output signal from H → L to turn off the power, and conversely, when the battery voltage exceeds the release voltage, the output signal changes from L → Control to turn on the power by setting to H. In order to prevent repeated detection and release due to fluctuations in battery voltage, and to prevent false detection due to noise, etc., the detection voltage and release voltage have hysteresis so that the relationship of release voltage> detection voltage is maintained. (See Patent Documents 1, 2, 4, etc.).

  In the example of FIG. 9, the release voltage for turning on the system power supply circuit 4 is determined by the voltage dividing ratio of the resistor 201 and the resistor 202 and the resistor 203, and the detection voltage for turning off the system power supply circuit 4 is , Determined by the voltage division ratio of the resistor 202 and the resistor 203. Similarly, the release voltage for turning on the low-voltage drive device power supply circuit 13 is determined by the voltage dividing ratio of the resistor 301, the resistor 302, and the resistor 303, and the low-voltage drive device power supply circuit 13 is turned off. The detection voltage for this is determined by the voltage dividing ratio of the resistor 302 and the resistor 303.

That is, when the input voltages of the comparators 204 and 304 are lower than the reference voltages 205 and 305, the output signals of the comparators 204 and 304 are H (the outputs of the voltage detectors 20 and 30 are L), so the FETs 207 and 307 Becomes OFF. Therefore, the reference voltage of the reference voltage generation circuits 205 and 305 is V _REF , and the resistance values of the resistors ₂₀₁ , ₂₀₂ , ₂₀₃ , ₃₀₁ , ₃₀₂ , and ₃₀₃ are respectively R ₂₀₁ , R ₂₀₂ , R ₂₀₃ , R ₃₀₁ , R ₃₀₂ , _Assuming R ₃₀₃ , the release voltages for charging the main battery 1 to turn on the system power supply circuit 4 and the low voltage drive device power supply circuit 13 are respectively
V _REF (R ₂₀₁ + R ₂₀₂ + R ₂₀₃ ) / R ₂₀₃
V _REF (R ₃₀₁ + R ₃₀₂ + R ₃₀₃ ) / R ₃₀₃
It becomes.

When the battery 1 is charged and its voltage exceeds the release voltage, the output signals of the comparators 204 and 304 are L (the outputs of the voltage detectors 20 and 30 are H), the FETs 207 and 307 are turned on, and the resistors 201 and 307 are turned on. Since 301 is short-circuited, the voltage dividing ratio of the battery voltage input to the comparators 204 and 304 is increased. Therefore, after that, the battery voltage is reduced due to the consumption of the battery accompanying the use of the portable communication device, and the detection voltage for turning off the power supply circuit 4 for the system and the power supply circuit 13 for the low voltage drive device is respectively
V _REF (R ₂₀₂ + R ₂₀₃ ) / R ₂₀₃
V _REF (R ₃₀₂ + R ₃₀₃ ) / R ₃₀₃
It becomes.

  The release voltage and detection voltage of the voltage detector 30 are set to values lower than the release voltage and detection voltage of the voltage detector 20, respectively.

  FIG. 10 is a timing chart showing system start-up and shutdown control operations in the conventional voltage detectors 20 and 30.

  8 to 10, when the output signals of the voltage detectors 20 and 30 are L, the FETs 207 and 307 are OFF. When the voltage of the main battery 1 rises due to charging or the like, first, when the release voltage of the voltage detector 30 is exceeded, the output signal of the voltage detector 30 changes from L to H, the FET 307 changes from OFF to ON, and the low voltage drive device turns on. . When the voltage of the main battery 1 further rises and exceeds the release voltage of the voltage detector 20, the output signal of the voltage detector 20 changes from L to H, the FET 207 changes from OFF to ON, and the system device is turned on.

  Next, when the battery is discharged due to the user operating the mobile communication device or the like, the battery voltage drops. When the battery voltage falls below the detection voltage of the voltage detector 20, the output signal of the voltage detector 20 changes from H → L, and the FET 207 turns on. → Turns off, shuts down the system and shuts down. When the voltage of the main battery 1 further decreases and falls below the detection voltage of the voltage detector 30, the output signal of the voltage detector 30 also changes from H → L, 307 changes from ON → OFF, and the power supply of the low voltage drive device is turned OFF. Shut down.

  At that time, first, when the voltage of the main battery 1 falls below the detection voltage of the voltage detector 20, the system power supply circuit 4 is turned off, the power supply to the system power supply circuit 4 and the system device is stopped, and low voltage driving is performed. Since power is supplied only to the device power supply circuit 13 and the low-voltage drive device 12, the power consumption is reduced, and the gradient of the battery voltage drop is gradual. Thereafter, the low voltage drive device 12 can be operated until the battery voltage falls below the detection voltage of the voltage detector 30 and the power supply to the power supply circuit 13 for the low voltage drive device is stopped.

Japanese Patent Application Laid-Open No. 08-271552 Japanese Patent Laid-Open No. 11-258280 Republished WO2002-073770 JP 2005-110425 A Japanese Patent Laid-Open No. 2006-246689

  According to the above prior art, even when the system power supply 4 is turned off because the battery voltage of the main battery 1 falls below the detection voltage operable as a portable communication device, the power supply 13 for the low voltage drive device such as Felica is Since the ON state can be maintained for a while, it is possible to continue using the low-voltage drive device 12 during that time.

  Therefore, if the detection voltage of the voltage detector 20 is set to a higher voltage and the system power supply circuit 4 is controlled to be turned off earlier, the power supply 13 for the low-voltage drive device with a gradual gradient of the battery voltage drop can be obtained. Only the power supply time can be extended, and the operation time of the low-voltage drive device 12 such as Felica can be set longer, but in this case, the original operation time of the mobile communication device system is shortened. There is a concern that setting the detection voltage to a higher voltage involves a change in hardware.

  Furthermore, the functions and functions of portable communication devices have been advanced, and the standby power of the system when not in use is increasing as the functions increase. Therefore, when the detected voltage is brought close to the release voltage, when the battery voltage becomes lower than the detected voltage and the system power switch is switched from ON to OFF, the battery voltage rises momentarily and becomes higher than the release voltage. There is a possibility that the power switch is repeatedly turned ON / OFF and the operation becomes unstable. In order to prevent this, it is necessary to increase the difference between the release voltage and the detection voltage, and there is a problem in that the detection voltage of the voltage detector 20 cannot be increased too much.

  The objective of this invention is providing the technique which controls the power supply to each function part in a portable electronic device which can solve the subject mentioned above.

  A power supply control method for a portable electronic device according to the present invention includes a system power supply circuit that supplies a voltage from a main battery to various main devices, and a low-voltage drive device that supplies a voltage from the main battery to a low-voltage drive device A power supply control method for a portable electronic device including a power supply circuit for a battery, wherein the battery voltage is monitored by monitoring a battery voltage of the main battery so that the battery voltage is a predetermined first voltage (hereinafter referred to as a first release voltage). When the above is reached, control is performed to turn on the system power supply circuit. When the battery voltage falls below a predetermined second voltage (hereinafter referred to as a first detection voltage), the system power supply circuit is turned on. When the battery voltage becomes equal to or higher than a predetermined third voltage (hereinafter, referred to as a second release voltage), the control for turning on the power supply circuit for the low-voltage drive device is performed. When the battery voltage becomes equal to or lower than a predetermined fourth voltage (hereinafter referred to as the second detection voltage), the power supply circuit for the low voltage drive device is controlled to be turned off and the system power supply circuit is turned on. The battery voltage of the main battery is periodically measured when the battery voltage is controlled, and when the measured battery voltage data falls below a preset voltage data, the first detection voltage is shifted to a predetermined voltage. It is characterized by pulling up.

  A power supply control circuit for a portable electronic device according to the present invention includes a power supply circuit for a system that supplies a voltage from a main battery to various main devices, and a low-voltage drive device that supplies a voltage from the main battery to a low-voltage drive device And monitoring the battery voltage of the main battery, and controlling the system power circuit to be turned on when the battery voltage becomes equal to or higher than a predetermined first voltage (hereinafter referred to as a first release voltage). When the battery voltage becomes equal to or lower than a predetermined second voltage (hereinafter referred to as a first detection voltage), a system power supply voltage detector that controls to turn off the system power supply circuit, and the main battery Control that monitors the battery voltage and turns on the power supply circuit for the low-voltage drive device when the battery voltage becomes equal to or higher than a predetermined third voltage (hereinafter referred to as a second release voltage). And a voltage detector for a low voltage drive device that performs control to turn off the power supply circuit for the low voltage drive device when the battery voltage becomes equal to or lower than a predetermined fourth voltage (hereinafter referred to as a second detection voltage); The battery voltage of the main battery is periodically measured when the system power supply circuit is controlled to be ON, and when the measured battery voltage data is equal to or lower than preset voltage data, Detection voltage shift means for raising one detection voltage to a predetermined voltage.

  The program according to the present invention includes a computer that periodically measures the battery voltage of a main battery that supplies power to the system power supply circuit when the system power supply circuit is controlled to be ON. When the detected battery voltage data is equal to or lower than the preset voltage data, the detection voltage set for the battery voltage is shifted to a predetermined voltage and turned up to turn off the system power supply circuit. It is made to function as a detection voltage shift means.

  In the present invention, since the system can be intentionally shut down by actively controlling the detection voltage of the monitored voltage detector, the standby power during sleep of the system after the shutdown is reduced. It can be assigned to drive a device operating at a low voltage, and the operating time of a device operating at a low voltage such as Felica can be extended.

  In addition, since the threshold voltage of the operable voltage range of the portable communication device can be freely changed, it is possible to programmably cope with the lower operating voltage of the device on the system side.

  FIG. 1 is a schematic block diagram including a power supply system configuration of a portable communication device showing an embodiment of the present invention.

  The portable communication device of this embodiment includes a Li-ion type main battery 1, voltage detectors 2 and 3 that monitor the battery voltage, a system power supply circuit 4 for supplying power to each device, baseband control, and the like. Communication system device 5, display system device 6 such as LCD display, interface 7 such as I / O, device 8 for application such as sound source and camera, control system device 9 such as CPU and memory, key input, etc. A data input unit 10, an A / D converter 11 that measures battery voltage, temperature, etc. according to instructions from the control system device 9, a low-voltage drive device 12 that drives even after the system shuts down, such as Felica and clock functions, and the low-voltage drive device The power supply 13 is configured.

  The voltage detector 2 for system power supply monitors the battery voltage of the main battery 1 and performs control to turn on the system power supply circuit 4 when the battery voltage becomes equal to or higher than a predetermined voltage (hereinafter referred to as release voltage). Then, the power supply of the main battery 1 is supplied to the device connected thereto, and when the battery voltage becomes equal to or lower than a predetermined voltage (hereinafter referred to as a detection voltage), the system power supply circuit 4 is controlled to be turned off. In addition, the device connected thereto is shut down, and when a detection voltage shift instruction is received from the control system device 9, the detection voltage is shifted to a predetermined voltage and raised.

  When the system power supply circuit 4 is controlled to be ON, the control system device 9 periodically operates the A / D converter 11 to measure the battery voltage data of the main battery 1, and the acquired battery voltage data When the voltage data is equal to or lower than the preset voltage data, a control signal for raising the detection voltage to a predetermined voltage is output to the voltage detector 2 for system power supply. The operation of the control system device 9 is realized by executing a program for shifting the detection voltage stored in the memory in the control system device 9 when receiving a shift instruction of the detection voltage from the user. .

  The voltage detector 3 for the low voltage driving device monitors the battery voltage of the main battery 1, and when the battery voltage becomes equal to or higher than a predetermined voltage (hereinafter referred to as a release voltage) that enables the low voltage driving device to operate, The power supply circuit 13 for the voltage driving device is controlled to be turned on, and the power of the main battery 1 is supplied to the low voltage driving device 12 so that the battery voltage becomes equal to or lower than a predetermined voltage (hereinafter referred to as detection voltage). At this time, the low voltage drive device 12 is shut down by performing control to turn off the power supply circuit 13 for the low voltage drive device.

  FIG. 2 is a circuit configuration diagram showing an example of a voltage detector 2 for a system power supply and a voltage detector 3 for a low-voltage drive device used in the power supply system for portable communication devices of this embodiment.

  The system power supply voltage detector 2 according to the present embodiment adds a resistor 208 as a voltage dividing resistor to the conventional system power supply voltage detector 20 shown in FIG. 8 and a control signal from the control system device 9. Therefore, the resistor 208 is forcibly short-circuited to shift the detection voltage to a predetermined voltage and raise the SW 209. The resistor 210 is for preventing the control signal from becoming indefinite when the system is in the shutdown state, and the detection voltage and the release voltage from changing depending on the state of the SW 209.

  The voltage detector 3 for the low voltage driving device has the same configuration as the voltage detector 30 for the conventional low voltage driving device shown in FIG. The voltage detector 2 for system power supply and the voltage detector 3 for low voltage drive device in the present embodiment are common in operation with the voltage detector 20 for system power supply and the voltage detector 30 for low voltage drive device shown in FIG. The description of the configuration of the parts to be performed is omitted.

  FIG. 3 is a timing chart showing system start-up and shutdown control operations in the voltage detector of this embodiment. The operation of this embodiment will be described below with reference to FIGS.

  When the output signals of the voltage detectors 2 and 3 are L, the FETs 207 and 307 are OFF and the SW 209 is OFF. The battery voltage input terminal of the comparators 204 and 304 is connected to the battery voltage of the main battery 1 with the resistor 201 and A voltage divided by the resistor 202, the resistor 203, and the resistor 208 and a voltage obtained by dividing the battery voltage of the main battery 1 by the resistor 301, the resistor 302, and the resistor 303 are input.

  When the voltage of the main battery 1 rises due to charging or the like, first, when the release voltage of the voltage detector 3 is exceeded, the output signal of the voltage detector 3 is changed from L → H, and the FET 307 is turned OFF → ON. Power is supplied. Further, when the voltage of the main battery 1 rises and exceeds the release voltage of the voltage detector 2, the output signal of the voltage detector 2 changes from L to H, and the FET 207 changes from OFF to ON, so that each device connected to the system power supply 4 operates. Power is supplied.

  Further, the control system device 9 periodically operates the A / D converter 11, periodically measures the battery voltage data of the main battery 1 converted into digital data by the A / D converter 11, and is set in advance. Compare with voltage data. In FIG. 3, a case will be described where the preset voltage data is set to a value equal to the release voltage of the voltage detector 2.

  Next, the battery is discharged due to the user's operation of the mobile communication device and the like, and the battery voltage drops, and the battery voltage data of the main battery 1 measured by the A / D converter 11 is the preset voltage data (implemented). In the example, when the voltage is equal to or lower than the release voltage, a detection voltage shift signal for raising the detection voltage to a predetermined voltage is output from the control system device 9 to the voltage detector 2 for system power supply.

When this detection voltage shift signal is input, the voltage detector 2 for system power supply switches the SW 209 from OFF to ON to short-circuit the resistor 208. Thereby, the detection voltage is
V _REF (R ₂₀₂ + R ₂₀₃ + R ₂₀₈ ) / (R ₂₀₃ + R ₂₀₈ )
To V _REF (R ₂₀₂ + R ₂₀₃ ) / R ₂₀₃
To be raised.

  The comparator 204 of the voltage detector 2 for system power supply, when the battery voltage of the main battery 1 falls below the detected voltage raised above, the output signal of the voltage detector 2 is changed from H → L, and the FET 207 is turned ON → OFF. Shut down systems other than low-voltage devices by switching to. As a result, standby power consumed on the system power supply circuit 4 side can be reduced, and the operation time of a low-voltage device with a gradual gradient of battery voltage decrease can be made longer than in the prior art.

  At this time, there is no problem even if the detection voltage raised is higher than the release voltage, but the battery voltage when raising the detection voltage is preferably lower than the release voltage.

  When the detection voltage is raised when the battery voltage is higher than the release voltage, the SW209 is first turned ON and the divided voltage input to the comparator 204 becomes lower than the reference voltage, and the detector output becomes H → The system is shut down and the system is shut down. At that time, the SW 209 is turned off. Therefore, the detector 2 monitors the battery voltage, detects that the voltage is higher than the release voltage, and sets the detector output to L → H again. As a result, a repeated detection / release operation may occur between the raised detection voltage and the release voltage. In order to avoid this, it is desirable to raise the detection voltage when the battery voltage falls below the release voltage.

  Thereafter, when the battery voltage falls below the detection voltage of the voltage detector 3, the power supply to the power supply circuit 13 for the low voltage drive device is also stopped.

  FIG. 4 shows a configuration part for monitoring the battery voltage using the AD converter 11 and sending a detection voltage shift signal to the voltage detector 2 in this embodiment, and FIG. 5 shows the configuration of FIG. Basically, a power supply control setting sequence is shown in which a detection voltage shift signal is transmitted when the voltage becomes equal to or lower than the release voltage. Hereinafter, the detection voltage shift signal transmission operation in the present embodiment will be described in detail with reference to FIGS.

  The controller 9 sends a request signal to the AD converter 11 so as to monitor the battery voltage (A1). In accordance with this request signal, the AD converter 11 inputs the battery voltage of the main battery 1 and performs A / D conversion (A2). The controller 9 obtains battery voltage AD conversion data from the A / D converter 11 (A3), and compares the data with preset voltage data (A4). In this case, it is desirable that the preset voltage data is equal to or lower than the release voltage of the voltage detector 2 and equal to or lower than the detection voltage shifted by the SW 209.

  This is to ensure that the shutdown can occur and to avoid the simultaneous occurrence of the shutdown and release, but in reality, there is an error due to variations in the detection voltage and AD conversion data when shifted on the detector side. Yes, if the system does not shut down, repeated retry will eventually cause a shutdown unless charging is started.

  When it is determined that the acquired battery voltage data is higher than the preset data (A4, No), an AD conversion request is made again after a predetermined time (returns to A1). Conversely, when it is determined that the battery voltage data is lower than the preset data (A4, Yes), a detection voltage shift signal is sent from the control unit 9 to the voltage detector 2 (A5). As a result, in the voltage detector 2, the detection voltage is shifted to the higher side and compared with the battery voltage (A6). At this time, if the battery voltage is higher than the shifted detection voltage (A6, No), the system is not shut down, and the AD conversion is requested again after a predetermined time.

  In this case, the detection shift signal is canceled and the detection voltage is returned (A7). This is to avoid a state in which the detection voltage remains shifted when shutdown processing is not performed. Conversely, when the battery voltage is lower than the shifted detection voltage (A6, Yes), an OFF signal is output from the voltage detector 2 and the system is shut down (A8). As a result, the current consumption of the system itself is eliminated, and only the device driven at a low voltage is in an operating state (A9).

  In FIG. 6, the power supply control sequence is shown using a timing chart.

  When the AD converted battery voltage data is higher than the preset data, the detection voltage shift signal is not output. In addition, when the battery voltage data subjected to AD conversion is lower than the preset data, a detection voltage shift signal is output, but an error due to variation between the actual detection voltage shifted by the detector and the AD conversion data. If there is, it indicates that the system will not shut down. In this case, the detection voltage shift signal is canceled by changing H → L, and the AD conversion request is retried. Further, when the battery voltage decreases and falls below the shifted detection voltage, a shutdown occurs.

  FIG. 7 is a flowchart showing another embodiment in which the power supply control setting sequence of FIG. 5 is changed.

  The battery voltage data obtained in steps B1 to B3 is compared with preset data (B4). When the battery voltage data is lower (B4, Yes), a detection voltage shift signal is output (B5), but it is not detected on the detector side due to errors in the AD converter 11 or variations in the detection voltage of the voltage detector 2. In some cases, the shutdown does not occur (B6, No). In this case, the detection voltage shift signal is once canceled (B7), and the battery voltage data at that time is set as detection data (B8).

  The battery data obtained by the next AD conversion is compared with newly set detection data, that is, the previous battery voltage data (B4). If the new battery voltage data is lower, a detection voltage shift signal is sent (B5), and if detected on the voltage detector side (B6, Yes), the system shuts down (B9). On the contrary, when the voltage detector does not detect (B6, No), the detection data is set to the battery voltage data at that time, and the sequence from the battery voltage monitor request (B1) to the AD converter operates again. The detection data is updated until is shut down.

  When this sequence is operated from the next time, the finally set detection data value becomes comparison data with the battery voltage data after AD conversion. Therefore, it depends on the variation error of the AD converter and the detection voltage error of the detector. The system shuts down whenever there is no sequence return and a shift signal of the detection voltage is sent.

It is a schematic block diagram including the power supply system structure of the portable communication apparatus which shows embodiment of this invention. It is a circuit block diagram which shows an example of the voltage detector for system power supplies and the voltage detector for low voltage drive devices used with the power supply system for portable communication apparatuses of this embodiment. It is a timing chart which shows operation of system start-up and shutdown control in the voltage detector of this embodiment. It is a block diagram which shows the component which sends out the detection voltage shift signal in this embodiment. It is a flowchart which shows the Example of the power supply control setting sequence which sends out the signal of the detection voltage shift in this embodiment. It is a timing chart of the power supply control setting sequence which sends out the signal of the detection voltage shift in this embodiment. It is a flowchart which shows the other Example of the power supply control setting sequence which sends the signal of the detection voltage shift in this embodiment. It is a block diagram which shows the power supply system structure of the conventional portable communication apparatus. It is a circuit block diagram which shows an example of the voltage detector for system power supplies and the voltage detector for low voltage drive devices which are used with power supply systems, such as the conventional portable communication apparatus. It is a timing chart which shows the operation | movement of system start-up and shutdown control in the conventional voltage detector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main battery 2,20 Voltage detector for system power supply 3,30 Voltage detector for power supply of low voltage drive device 4 System power supply 5 Communication system device 6 Display system device 7 I / O
8 Application devices 9 Control system devices (CPU, memory, etc.)
DESCRIPTION OF SYMBOLS 10 Data input part 11 A / D converter 12 Low voltage drive device 13 Power supply for low voltage drive devices 201,202,203,208,210,301,302,303 Resistor 204,304 Comparator 205,305 Reference voltage 206,306 Inverter 207,307 FET
209 switch

Claims (12)

A power supply for a portable electronic device comprising a power supply circuit for a system that supplies a voltage from a main battery to various main devices and a power supply circuit for a low-voltage drive device that supplies the voltage from the main battery to a low-voltage drive device A control method,
By monitoring the battery voltage of the main battery, when the battery voltage becomes equal to or higher than a predetermined first voltage (hereinafter referred to as a first release voltage), the system power supply circuit is turned on, and the battery voltage is When the voltage falls below a predetermined second voltage (hereinafter referred to as a first detection voltage), hysteresis control is performed to turn off the system power supply circuit, and the battery voltage is set to a predetermined third voltage (hereinafter referred to as a second voltage). The low-voltage drive device power supply circuit is turned on when the battery voltage becomes equal to or lower than a predetermined fourth voltage (hereinafter referred to as second detection voltage). The hysteresis control for turning off the power supply circuit for the driving device is performed, and the battery voltage of the main battery is periodically measured when the power supply circuit for the system is controlled to be turned on. When ponds voltage data is equal to or less than a preset voltage data, the power control method characterized by raising shifts the first detection voltage to a predetermined voltage. The first release voltage, the first detection voltage, the second release voltage, and the second detection voltage are:
2. The power supply control method according to claim 1, wherein the first release voltage> the second release voltage> the first detection voltage> the second detection voltage.   3. The power supply control method according to claim 1, wherein the preset voltage data is set to be equal to or less than a value of the first release voltage and equal to or less than the shifted detection voltage. 4.   4. The power supply control method according to claim 1, wherein the operation of shifting the first detection voltage to a predetermined voltage is executed when the execution is selected. 5. A power supply circuit for a system that supplies a voltage from the main battery to various main devices;
A power supply circuit for a low-voltage drive device that supplies a voltage from the main battery to a low-voltage drive device;
The battery voltage of the main battery is monitored, and when the battery voltage becomes equal to or higher than a predetermined first voltage (hereinafter referred to as a first release voltage), the system power supply circuit is turned on, and the battery voltage is set to a predetermined first voltage. A system power supply voltage detector that performs hysteresis control to turn off the system power supply circuit when the voltage is equal to or lower than a voltage of 2 (hereinafter referred to as a first detection voltage);
The battery voltage of the main battery is monitored, and when the battery voltage becomes equal to or higher than a predetermined third voltage (hereinafter referred to as a second release voltage), control is performed to turn on the power supply circuit for the low voltage drive device, A voltage detector for a low voltage drive device that performs hysteresis control to turn off the power supply circuit for the low voltage drive device when the battery voltage becomes equal to or lower than a predetermined fourth voltage (hereinafter referred to as a second detection voltage);
When the system power supply circuit is controlled to be ON, the battery voltage of the main battery is periodically measured, and when the measured battery voltage data is equal to or lower than preset voltage data, the first battery voltage is measured. Detection voltage shift means for shifting the detection voltage to a predetermined voltage and pulling it up;
A power supply control circuit for a portable electronic device. The system power supply voltage detector switches the main voltage between a first voltage division ratio for detecting the first release voltage and a second voltage division ratio for detecting the first detection voltage. It has a plurality of voltage dividing resistors configured to give a hysteresis function,
The detection voltage shift means includes a switch connected in parallel with one of the plurality of voltage dividing resistors, battery voltage measuring means for periodically measuring the battery voltage of the main battery, and the battery voltage measurement. Means for controlling ON / OFF of the switch according to whether the battery voltage data measured by the means is less than or equal to preset voltage data;
The power supply control circuit for a portable electronic device according to claim 5. The first release voltage, the first detection voltage, the second release voltage, and the second detection voltage are:
7. The power supply control circuit for a portable electronic device according to claim 5, wherein the first release voltage> the second release voltage> the first detection voltage> the second detection voltage.   8. The preset voltage data is set to be equal to or less than a value of the first release voltage and equal to or less than a detection voltage shifted by the detection voltage shift means. 2. A power supply control circuit for a portable electronic device according to item 1.   The power supply control circuit for a portable electronic device according to any one of claims 5 to 8, further comprising means for enabling selection or non-operation of the detection voltage shift means.   A portable electronic device comprising the power supply control circuit according to claim 5.   The portable electronic device according to claim 9, wherein the portable electronic device is a mobile phone. Means for periodically measuring the battery voltage of a main battery that supplies power to the system power supply circuit when the system power supply circuit is controlled to be ON; and the measured battery voltage data Functions as detection voltage shift means for shifting the detection voltage set to the battery voltage to a predetermined voltage and raising it to turn off the power supply circuit for the system when the voltage data becomes less than or equal to preset voltage data Program to let you.

Images